Fuse plug



T. WOLD Dec. 18, 1934.

FUSE PLUG Filed March 17, 1934 jv vf/vTofL "lV-Werf WOLD Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE FUSE PLUG Canada Application March 17, 1934, Serial No. 716,147

1 Claim.

This invention relates to improvements in fuse plugs, and the objects of the invention are to generally improve and simplify the construction of the plug to better adapt it to perform the functions required of it.

Further objects are to enable the parts to be more readily assembled, to prevent breakage of the fragile parts during assembly and to prevent too rapid escape of gas from the interior of the plug in the event of the fuse blowing out. It consists essentially in the improved construction hereinafter described in detail in the accompanying speciiication and drawing.

In the drawing- Figure 1 is an elevation of the fuse plug embodied in the present invention.

Figure 2 is a longitudinal section of the fuse plug.

Figure 3 is a section on the line 3 3 of Figure 2.

Figure 4 is a sectional detail of the sealing Washer.

In the drawing like characters of reference indicate corresponding parts in all the figures.

Referring to the drawing, A indicates the base of the plug, preferably formed of transparent glass having molded threading on the outside of the base, the body portion of the base being of cylindrical Torm. B indicates a porcelain fuse-carrying member formed with a cylindrical portion 11 designed to iit the cylindrical portion on the base A, carrying at the end a contact member 12 in which one end of the fuse 13 is sealed, the other end of the fuse extending between the cylindrical portion 11 and the base A in a groove 14 and then being turned over the screw threading 10, where it contacts with the metallic shell or sleeve member C, which is also formed with screw threading and designed to 40 fit the usual socket with which the plug is used.

The porcelain member B is formed with an annular flange 15 adapted to abut the end of the base member, the outer side of the iiange being adapted to receive a flexible sealing washer D of iibrous material, such as cardboard or (Cl. 20D-130) paper, which is engaged by an inturned and inner flange 16 on the metal shell C.

It will be seen that the three main parts of the device may be rapidly assembled together, and it will be observed that the sealing washer D 5 will prevent the porcelain element from digging into the brass shell, thus allowing the shell to be tightened suiciently so that the brass may be upset slightly to clamp the glass top and porcelain case further together. This sealing 10 washer also acts as a cushion preventing the breakage of the glass and porcelain parts during assembly.

The washer performs another function in that it lls up the space between the porcelain and 15 the metallic shell, thus preventing the gas escaping through the bottom of the fuse. When the fuse blows the gas will have to pass between the shell and the glass, which will enable it to cool ofi sufiiciently before it is discharged externally from the plug.

Various modiiications may be made in the invention without departing from the spirit thereof or the scope of the claim and, therefore, the exact forms shown are to be taken as illustrative only and not in a limiting sense, and I desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set -:forth in the appended claim.

What I claim as my invention is: 30

A fuse plug comprising a base member having a cylindrical portion with external screw threading, a porcelain fuse-carrying member having a cylindrical portion adapted to extend within the cylindrical portion of the base member and having an annular iiange adapted to abut the top of tie cylindrical portion on the base member, a threaded metallic shell engaging the exterior of the base member having an internal flange adapted to extend over the flange on the porcelain member and a flexible sealing Washer extending between the iiange on the porcelain member and the iiange on the shell all as substantially set forth and described.

TRYGVE WOLD. 45 

